We saw something in the SA election on Saturday night that you just don’t see very often in Australian elections – a major skew in the swing. Often what happens when a swing is on against a government is that there’s a slight skew, where safe government seats swing very slightly more, on average, than government held marginal seats.
The last Fed election is a good example: if we scatter the pre-election, ALP two party preferred of each government held seat against the swing to the ALP that each seat experienced, we get a big cloud with a very slight but statistically insignificant trend involved:
If we run the exact same chart for what happened on Saturday in SA, where we use the Liberal Party TPP in government held seats going into the election and scatter it against the swing to the Liberal party in each, the result is pretty amazing:
Not only is the trend statistically significant, but it’s very, very strong.
The safer the government seat, the much larger was the swing against the government. In fact, for every 3 additional points of two party preferred vote above 50 that a Labor held seat enjoyed going into the election, the swing against the government increased by a full percentage point on average. I can’t remember an election where this relationship happened to this strength.
These sorts of highly non-uniform swings play complete havoc with our simulations when we don’t have any seat by seat, or region by region, or marginal vs whole electorate polling to feed into them, particularly in the probability tails.
Our point estimates look to be about 3 seats out (assuming Rann gets 24 seats), but our probability tails got hammered with the non-uniformity, suggesting that the likelihood of Rann winning at least 24 seats was only 8% – even though the Newspoll it was based on got within the MoE of the election result.
Why this happened can only be partially explained by Bruce Hawker’s resource allocation of Labor campaign spending. Labor focused most of their resources into retaining marginal seats including the political messages tailored to those marginals, letting the really safe seats take the full blow of the swing running against them, knowing that their margins were large enough to withstand such a swing. The point of an election is to win seats, not margins.
Yet, while the safe seats had large swings and the marginals had very small ones, the group of seats between the marginal and safe seats experienced a swing against them that was between the size of the swing suffered by the other two groups of seats.
That seemed to be achieved more by accident than political design – but it’s interesting that those middling seats came in consistent with the regression line (even though they have a larger variance in their results), suggesting that there might have been something else at play apart from the political strategy that gave us this strong relationship across the full spectrum of Labor held seats.
19 Comments
Maybe the electorate wanted to take to the Rann Government with their nerf-bats?
The loss of the heartland for labor does reflect the redundency of its traditional social base in my opinion. As piping shrike pointed out as Labor stopped being about ideology and stated becoming about technocratic government large swings in its traditional “base” are to be expected because said “base” has no real foundation in the ellectorate. As for why the swing was greater in the safe seats there could be a socio-economic reason for it, given the location of said safe seats. In any case considering the greatest swing was in seats neither side was heavilly campaigning in the Liberals cant really take the credit.
I think this is what it looks like when a party disconnects from its heartland.
In particular working class South Australians have woken up to the fact that personal freedoms they previously had have all been eroded under this government. Censorship in particular is an issue in the minds of many people. Put colloquially; people think Rann is a ‘fascist’.
The big question is can Labor win these people back? A change of Premier might be enough.
not that unusual. Howard did the same thing in ’98
Yes, like Shal said, it’s like Howard in 1998.
With the possible exception of Bright, in the seats the ALP lost the swing was actually much more than the Libs needed. I’d say Labor did a fairly shrewd job of identifying marginal seats that they could hold onto and throwing everything they could at them. I live in Norwood and got the impression that the ALP had already written the seat off as one they were going to lose before the campaign (makes you wonder why they didn’t encourage the incumbent to move on and give someone else a go). I certainly didn’t see any ‘put your Family First’ campaigners outside my polling booth!
Adelaide was probably the only true ‘shock’ result for Labor.
Shal, the 1998 election wasn’t really anything like this at all.
Here’s how the ALP swing in 1998 vs the TPP margins going into the election looked like
http://blogs.crikey.com.au/pollytics/files/2010/03/alp1998.PNG
Compare that to what has just happened in SA across all seats:
http://blogs.crikey.com.au/pollytics/files/2010/03/saallseats.PNG
Of course the Newspoll on Saturday morning in the News press was already triumphal for the Liberals…and the result showed what happens when you ignore the standard error of measurement.
Very interesting Possum. Do you happen to have the equivalent charts handy for the government seats in the latest QLD and WA elections?
Not handy Laocoon, but I can probably dig out the Qld ones by tomorrow (they’re laying around here somewhere).
I would suggest that a strong swing against government in its safe seats just means that the safety of those seats was over-stated previously.
Some of those seats have the Lib TPP being 20% and a whole bunch below 30%. Were they really on a 40% margin?
It can just be an artifact of the previous election where the opposition was hopeless and therefore the safe seats appeared to gain massive margins.
Thanks Possum…as you say, Labor’s allocation of resources may be partial explanation, but it does seem to me to be not the entire story. Perhaps an entirely random “SA 2010″ explanatory variable.
But I am wondering it is possible to discern any trend over the last year or 2 that might be indicative that there has been a “tipping point” in something; and that this change results in a marked break-down of the strength of uniform swings.
A potential candidate for the *something* could be TV news/newspaper penetration; a tipping point versus internet, targetted seat campaigns????
There a saying that when the swing is on, every candidate is affected. Clearly not in this election in South Australia.
It looks like a very focused marginal seat campaign. I don’t know if the Family First T-shirts would have had an affect.
EnergyPedant, I think you make valid points.
I live in Elder, where the swing against Labor was identical to the swing to Liberal. Whether this swing is the same body of voters packing their bags en mass from one major party to the other, I don’t know. But it does appear that the swing toward the Greens here has come entirely from voters dumping all the other minors and independents. So not much swing at all between the major and minor/independent party vote.
Interesting result indeed.
Actually on second thought, maybe I should just come out and say that it looks like the Libs took a swathe of Labor voters, and support for the minors and independents has rallied behind the Greens.
Feel better now.
Actually the heartland seats all had massive and unsustainable majorities and they were always going to be corrected this time around.
The best news is Mad Mick resigning as AG.
EnergyPedant/shepherdmarilyn
Would a test of your theory be, that at the previous election, there would have a been a reverse skew to that we saw this time around?
Possum do you know if that is true? (aint it a burden when you come up with something really interesting, people pester you for more!
)
shepherdmarilyn:
I’ve only been back in Adelaide for six months, but I’ve read a few unsavoury pieces on ‘Mad Mick’ already. I also understand that Mike Rann’s time is basically up. He can thank his lucky stars that it looks like Labor will get across the line this time, but he’s simply got to make way for someone else during this term. That, at least, would give Labor a current face for the next election. I can’t see any public redemption from this (alleged) sex scandal thing eventuating unless some independent body comes along and says, “Nope, it never happened”. And I wouldn’t bet on it, either.
Forget who the soap opera nonsense of did he or didn’t he sahag some trollop… Con Makris – Le Cornu’s.. nuff said.